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Abstract

In the title N-alkyl isatin, C18H25NO2, the isatin moiety is almost planar (r.m.s. deviation = 0.03 Å). C—C—C—C torsion angles of the decyl substituent indicate an all-antiperiplanar conformation.

Acknowledgments

We thank Université Mohammed V-Agdal and the University of Malaya for supporting this study.

supplementary crystallographic
information

Comment

N-Substituted isatins (Bouhfid et al., 2008) represent a
large
family of heterocyclic compounds reported to show a wide range of useful
medicinal activities. These are readily synthesized by the reaction of isatin
and an alkyl halide in the presence of a catalyst. The title decyl derivative
(Scheme I, Fig. 1) has a particarly long hydrocarbon chain; the chain adopts a
extended zigzag conformation.

The crystal structures of only few N-substituted isatins have been
reported; these have only short hydrocarbon chains, e.g., methyl isatin (Miehe
et al., 2003) and ethyl isatin (Naumov et al.,
2002).

Experimental

To a solution of isatin (1 g, 6.8 mmol) dissolved in DMF(50 ml) was added
1-bromodecane (1.50 g, 6.8 mmol), potassium carbonate (1 g, 7.4 mmol) and a
catalytic quantity of tetra-n-butylammonium bromide.The mixture was
stirred for 48 h; the reaction was monitored by thin layer chromatography. The
mixture was filtered and the solvent removed under vacuum. The solid that was
obtained was recrystallized from ethanol to afford the title compound as
orange crystals in 80% yield.

Refinement

H-atoms were placed in calculated positions (C–H 0.95–0.99 Å)
and were included in the refinement in the riding model approximation, with
U(H) set to 1.2–1.5Ueq(C).